stimuli presented to the dark-adapted eye have been

Purpose To evaluate rod and cone contributions to the dark-adapted 15-Hz flicker electroretinogram (ERG) across a broad range of stimulus luminances by compar-ing rod-isolating (ERGR), cone-isolating (ERGC), and non-receptor-specific (ERGR?C) responses. Methods Dark-adapted, full-field 15-Hz ERGs were obtained from four normally sighted subjects (ages 29–36 years) using a four-primary LED-based stimulat-ing system. The primaries were either modulated sinusoidally in phase (ERGR?C) or were modulated in counter-phase to achieve rod isolation (ERGR) or cone isolation (ERGC) by means of triple silent substitution. Measurements were made for a broad range of luminances (-2.5 to 1.8 log scot. cd/m2 in 0.2 log uni